外源乙烯对长春花生理水平和生物碱积累的影响

药用植物长春花中含有100多种萜类吲哚生物碱（TIAs），其中具有抗肿瘤功效的长春碱和长春新碱受到关注。为了研究外源乙烯处理对长春花生长情况、生理状态和萜类吲哚生物碱合成的整体影响，本文以长春花幼苗为实验材料，使用外源乙烯处理后对比了不同生长条件下长春花的生物量积累、根茎伸长、光合参数以及生物碱含量等指标，分析了生物碱合成与其他指标之间的相关性。结果表明，外源乙烯处理使长春花乙稀释放量上升，乙烯信号响应因子erf基因表达量提高。乙烯利抑制长春花幼苗生物量积累、根纵向生长，促进茎秆横向加粗生长，由非气孔因素导致净光合速率（P_n）和气孔导度（G_s）下降。外源乙烯促进异胡豆苷（STR）、长春质碱（CAT）、文多灵（VIN）和长春碱（VINB）积累，并且促进长春碱合成途径中关键酶基因str和CrPRX上调表达。相关性分析结果表明，次生代谢产物的积累、生长指标、光合参数之间存在明显的相关性；长春质碱、文多灵、长春碱与茎秆直径（SD）显著正相关（P < 0.05），与生物量（B）、株高（H）、根长（RL）、净光合速率（P_n）呈显著负相关（P < 0.05）。本文为研究外源乙烯调控长春花生物碱积累的机制提供理论基础。

Effects of Exogenous Ethylene on Physiology and Alkaloid Accumulations in Catharanthus roseus

Catharanthus roseus, as a medicinal plant, contains more than 100 terpenoid indole alkaloids(TIAs), including vinblastine and vincristine which focus on anti-cancer effects. In order to study the comprehensive influence of exogenous ethylene on growth, physiology, and terpenoid indole alkaloid accumulations, C.roseus seedlings were cultured as experimental material and contrasted the data of biomass, growth rate of root and stem, photosynthetic parameter and alkaloid contents with or without ethephon treatment, and the correlations between these indexes were analyzed. The ethylene release amount and the expression of erf(ethylene-response factor) gene were increased under exogenous ethylene treatment. Ethephon inhibited biomass, longitudinal growth but promoted lateral thickening growth of stem; in addition, net photosynthetic rate(P_n) and stomatal conductance(G_s) were decreased leading from non-stomatal factor. The biosynthesis of four alkaloids including strictosidine(STR), catharanthine(CAT), vindoline(VIN) and vinblastine(VINB) were accelerated in ethephon-treatment group, and the expression of key enzyme genes(str and CrPRX) were up-regulated by ethephon. By correlation analysis, we found that relationships among alkaloid contents, growth indexes and photosynthetic parameters were significant and photosynthetic parameters were significant. It were positive relation between three alkaloids including CAT, VIN, VINB and stem diameter(SD)(P < 0.05). On the contrary, there was a significantly negative relations between these three alkaloids and biomass(B), height(H), root length(RL), net photosynthetic rate(P_n)(P < 0.05). Our study will provide useful information for mechanism research of exogenous ethylene regulating TIAs biosynthesis in C.roseus.